Journal of Microbiological Methods 10 (1989) 71 - 82 71 Elsevier MIMET 00325 Comparison of methods for the evaluation of the oral microbiota of mice Lynda Rodrigue, Diane Marion, Luc Trudel, Christine Barthe and Marc C. Lavoie Groupe de Recherche en Ecologic Buccale (GREB), ,¢~colede Mddecine Dentaire et D#partement de Biochimie, Universitd Laval, Qu#bec, Canada (Received 2 February 1989; revision received 1 May 1989; accepted 8 May 1989) Summary To develop a mouse model, in which we could study the effect of environmental parameters on oral microbial populations, suitable sampling and microbial identification techniques were needed. Four methods of bacterial detection, i.e., indirect microimmunofluorescence,immuno-dot-blot, immuno-colony- blot and selective media, were compared using known mixtures of bacteria previously isolated from mice and freshly collected samples from the oral cavity of BALB/c mice. Furthermore, three methods of sampling the oral cavity, i.e., collection of saliva, swabbing and tissue dissection, were used to compare the bacterial distribution of the oral microflora. Our results indicate that swabbing is the superior sampling method and that the immuno-colony-blot assay is the more suitable technique for the detection of the different bacterial species present in the samples. Key words: Immuno-colony-blot; Immuno-dot-blot; Microimmunofluorescence; Oral microbiology; Selective medium Introduction To study the effect of environmental parameters on the bacterial populations of the oral cavity, we developed a mouse model [1] which has already been immunologically [2- 7] and bacteriologically [8 - 10] characterized. However, the methods used to ana- lyse the bacterial populations were cumbersome and time-consuming and do not per- mit one to easily follow the evolution of these populations in the same animal [9]. In this paper, we compare three methods of sampling the oral cavity, i.e., collection of saliva, swabbing and dissection of the teeth, tongue and mucosa, and four methods of bacterial detection, i.e., indirect microimmunofluorescence, immuno-dot-blot, Correspondence to: M. C. Lavoie, Groupe de Recherche en l~cologie Buccale (GREB), l~cole de M6decine Dentaire et D6partement de Biochimie, Universit6 Laval, Qu6bec G1K 7P4, Canada. 0167-7012/89/$ 3.50 © 1989 Elsevier Science Publishers BN. (Biomedical Division)